Figure 9-14 Example Of Gated Signals For Velocity Calibration - Olympus EPOCH 650 User Manual

12. Adjust the gain so that neither signal is saturated, and so that the echo amplitude
in gate 2 is above 50 %.
A thickness measurement reading appears in large text above the A-scan, labeled
2-1.
In attenuating materials, it might be impossible to bring the second indication above
50 % while avoiding saturation of the first signal. If this is true, try using the Edge
detection mode instead of the peak detection to ensure accurate measurements (see
"Gate Measurement Modes" on page 126 for details).
Ensure that gate 1 and gate 2 are capturing successive back-wall echoes, not multiple
echoes from the end of the delay line tip.

Figure 9-14 Example of gated signals for velocity calibration

DMTA-10055-01EN, Rev. A, February 2015
Thickness measurement
Calibration 163